Why do Babies Spit Up and What can we do About it?

From Nancy:

Spitting up can trigger a host of worries in new parents, some related to their role in this behavior and others to do with baby’s growth and health.

  • Was it something I did?
  • Was it something I ate?
  • Will my baby’s weight gain suffer with the loss of so much milk?
  • Does my baby have reflux disease?

Along with these concerns, parents often ask themselves “What should I do next?” Here are the answers to these and other questions.

Is Spitting Up Ever Normal?

Yes, because most young babies (between 50% and 70%) spit up at least some of the time.1 Why? In the early months, the sphincter muscle that keeps the milk in the baby’s stomach has low tone and relaxes often. On average, several times each day a baby’s stomach contents wash back into her esophagus. Known as reflux, this is normal in both children and adults.

Normal reflux becomes spitting up when the baby’s stomach contents make it all the way up her esophagus and out of her mouth. Spitting up peaks between 3 and 5 months, occurring less and less often as the digestive system matures and baby spends more time upright. By 12 months, only 4% to 10% of babies spit up.2

Vomiting and spitting up are not the same. Usually, babies vomit when they are ill and spit up (or “spill”) when they’re not. Often, spitting up happens after feeding. Sometimes babies bring up a little milk and sometimes a lot. Even if it looks like much milk is lost, spitting up is not a cause for concern when the baby is gaining weight as expected and feeding well. Sometimes called “happy spitters,” think of spitting up in these babies as a temporary inconvenience that will resolve on its own over time. Some refer to this as a laundry problem, not a medical problem. See the later “Strategies” section for tips to minimize spitting up.

Can Overfeeding Cause Spitting Up?

Sometimes yes. Babies who directly nurse are less likely to overfeed than babies who are bottle-fed, no matter what’s in the bottle.3 But overfeeding can happen with direct nursing, too, when parents produce much more milk than the baby takes (oversupply, aka hyperlactation) and especially when they regularly coax their babies to keep nursing after they are done.4 Babies who are fast nursers can sometimes take all they need in just 5 minutes.

Nursing babies are less likely to overfeed and spit up in part because on average they consume less milk per feed than they do during a bottle-feeding. Why? During nursing, milk flow is fast during milk ejections (parents average five per feed, even though most don’t feel them all) and slower in between. These periods of slower milk flow between milk ejections gives babies time to realize they’re full and stop nursing before they overfeed.

Unless paced bottle-feeding is used (described HERE), which makes bottle-feeding more like nursing, during bottle-feeding, milk flow from the bottle is consistently fast. When babies eat too fast (just like adults), they are more likely to overeat. Regular overfeeding doesn’t just trigger more spitting up, it also increases risk of child overweight and obesity.3 See the later “Strategies” section for tips to prevent overfeeding.

Can Something I Ate Cause My Baby to Spit Up?

Many parents worry about this, but although it is possible, it is unlikely. An allergy or hypersensitivity to something in the nursing parent’s diet that passes into the milk occurs in only about 1% to 5% of exclusively nursing babies. 5,6 When it happens, the most common culprit is dairy, and in addition to spitting up, there are almost always other physical symptoms, such as a skin rash, congestion, or frothy, bloody, or mucusy stools. An allergy or sensitivity sometimes mimics symptoms of GERD (next section), as it may also cause irritation of the esophagus.7

An exclusively nursing parent can rule in or out allergy to cow’s milk by avoiding all forms of dairy, including milk, yogurt, ice cream, cheese, and butter, plus anything containing casein and whey.8 It may take up to 4 weeks to see a significant improvement in the baby’s symptoms,7 but there is often some improvement within a few days. If the baby is also receiving formula (most are cow-milk based), use a hypoallergenic type until allergy is ruled out. 

Does Spitting Up Mean My Baby Has GERD?

When the normal reflux described in the second paragraph causes damage to the lining of the esophagus, this is called gastroesophageal reflux disease (GERD). A baby with GERD may or may not spit up, because damage to the esophagus can occur even if the stomach contents don’t make it all the way to the baby’s mouth (called “silent reflux”).

spitting up

Nursing with baby’s head higher than bottom can help

GERD can cause congestion, coughing, and other respiratory problems. The baby’s irritated esophagus may make feeding painful.9 Some upsetting behaviors linked to GERD include irritability, poor weight gain, back arching and head turning, and feeding distress.9

GERD symptoms are sometimes attributed to “colic,”10 a term used to describe regular and unexplained periods of crying in babies younger than 3 to 4 months. If GERD is suspected, it’s time for baby to see her healthcare provider.

A treatment sometimes suggested for formula-fed babies with GERD is adding cereal or starch to formula to thicken it as a way to reduce the number of reflux episodes.1 Also, pre-thickened formulas are sold for babies with GERD.

But thickening milk and giving solids before 6 months are not recommended for nursing babies with GERD. No evidence supports thickening milk for nursing babies11 and the American Academy of Pediatrics does not recommend it.1 See the next-to-last section “Will Switching to Formula Help” for research comparing the effects of direct nursing, formula-feeding, and solids on reflux, spitting up, and GERD.

Are There Other Physical Causes of Spitting Up?

Some speculate that tongue-tie contributes to spitting up, but research does not yet confirm or refute this possibility.

If spitting up happens more and more often and becomes projectile (milk shooting a distance from baby), it’s time for baby to be evaluated by her healthcare provider. Some babies with these symptoms have a condition called pyloric stenosis that can hinder baby’s weight gain and growth and needs immediate treatment.

Strategies That Minimize Spitting Up

spitting up

When wiping baby, roll her on her left side rather than lifting her legs

If baby is spitting up for any reason, these basic strategies may help. A 2013 study of babies with GERD12 found they improved symptoms by 50%.

  • Positional therapy means keeping baby’s head above bottom as much as possible. Nurse with baby’s head higher than her bottom. After feeds, keep baby upright for 20 to 30 minutes in arms or in an upright baby carrier.
  • When baby is awake and horizontal, lay her on her left side or tummy. The baby’s esophagus connects to the stomach near her back, and lying tummy down triggers less reflux than back-lying.
  • Offer smaller, more frequent feeds. A nursing baby between 1 and 6 months needs on average about 25 oz. (750 mL) every 24 hours to grow and thrive. Taking less milk more often means less milk in the stomach to wash back into the esophagus and less time with an empty high-acid-content stomach. If oversupply is an issue, avoid prolonging feeds if baby seems done. If baby is bottle-feeding, pace them as described in THIS free handout.
  • Avoid putting baby in a car seat when not in a moving car, as this position increases reflux episodes.13

If the baby who spits up also has a rash, congestion, or unusual stools, to rule out allergy, try eliminating dairy for a few weeks to see if that makes a difference.

Will Switching to Formula Help?

Some parents wonder if nursing is the cause of their baby’s spitting up. Some healthcare providers suggest weaning babies with GERD to formula under the mistaken assumption that it will help.

spitting up

Avoid car seats unless baby is in a moving car

Unfortunately, giving formula is linked to more reflux episodes, more spitting up and can make GERD symptoms worse. Direct nursing, on the other hand, reduces reflux episodes. In 2017, a U.S. study using data from more than 2,800 babies14 compared how feeding method affected reflux episodes. Some babies directly nursed, some were formula-fed, some did both, and some ate solids. They concluded that feeding solids did not reduce reflux in nursing babies and that formula- and bottle-feeding increased the episodes of reflux.

In Belgium, researchers found that exclusively nursing babies spit up less than nursing babies who also received formula.2 After examining medical records, Italian pediatricians15 found that nursing babies stop spitting up earlier than babies fed formula.


For the vast majority of babies who spit up, this is just a normal—if messy—part of infancy that will gradually stop as they mature. But whether a baby’s spitting up is normal or it is triggered by overfeeding, allergy, GERD, or other causes, try the basic strategies described earlier. Anything that reduces laundry loads and house cleaning for new families is a definite plus.

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1  Lightdale, J. R., Gremse, D. A., Section on Gastroenterology, H., et al. (2013). Gastroesophageal reflux: Management guidance for the pediatrician. Pediatrics, 131(5), e1684-1695.

2.  Hegar, B., Dewanti, N. R., Kadim, M., et al. (2009). Natural evolution of regurgitation in healthy infants. Acta Paediatrica, 98(7), 1189-1193.

3  Azad, M. B., Vehling, L., Chan, D., et al. (2018). Infant feeding and weight gain: Separating breast milk from breastfeeding and formula from food. Pediatrics, 142(4).

4  Johnson, H. M., Eglash, A., Mitchell, K. B., et al. (2020). ABM clinical protocol #32: Management of hyperlactation. Breastfeeding Medicine, 15(3), 129-134.

5  Munblit, D., Perkin, M. R., Palmer, D. J., et al. (2020). Assessment of evidence about common infant symptoms and cow’s milk allergy. JAMA Pediatrics, 174(6):599-608.

6  Kvenshagen, B., Halvorsen, R., & Jacobsen, M. (2008). Adverse reactions to milk in infants. Acta Paediatrica, 97(2), 196-200.

7  Salvatore, S., & Vandenplas, Y. (2002). Gastroesophageal reflux and cow milk allergy: Is there a link? Pediatrics, 110(5), 972-984.

8  Heine, R. G. (2008). Allergic gastrointestinal motility disorders in infancy and early childhood. Pediatric Allergy and Immunology, 19(5), 383-391.

9  Semeniuk, J., & Kaczmarski, M. (2008). Acid gastroesophageal reflux and intensity of symptoms in children with gastroesophageal reflux disease. Comparison of primary gastroesophageal reflux and gastroesophageal reflux secondary to food allergy. Advances in Medical Sciences, 53(2), 293-299.

10  Vandenplas, Y., Badriul, H., Verghote, M., et al. (2004). Oesophageal pH monitoring and reflux oesophagitis in irritable infants. European Journal of Pediatrics, 163(6), 300-304.

11  Kwok, T. C., Ojha, S., & Dorling, J. (2017). Feed thickener for infants up to six months of age with gastro-oesophageal reflux. Cochrane Database of Systematic Reviews, 12, CD003211. doi:10.1002/14651858.CD003211.pub2.

12  Hegar, B., Satari, D. H., Sjarif, D. R., et al. (2013). Regurgitation and gastroesophageal reflux disease in six to nine months old indonesian infants. Pediatric Gastroenterology, Hepatology & Nutrition, 16(4), 240-247.

13  Carroll, A. E., Garrison, M. M., & Christakis, D. A. (2002). A systematic review of nonpharmacological and nonsurgical therapies for gastroesophageal reflux in infants. Archives of Pediatrics and Adolescent Medicine, 156(2), 109-113.

14  Chen, P. L., Soto-Ramirez, N., Zhang, H., et al. (2017). Association between infant feeding modes and gastroesophageal reflux: A repeated measurement analysis of the Infant Feeding Practices Study II. Journal of Human Lactation, 33(2), 267- 277.

15  Campanozzi, A., Boccia, G., Pensabene, L., et al. (2009). Prevalence and natural history of gastroesophageal reflux: Pediatric prospective survey. Pediatrics, 123(3), 779-783.

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